import java.io.IOException;
import java.util.Scanner;
public class Main{
    public static void main(String[] args) throws IOException {
        Main main = new Main();
        main.startup();

    }

    public void printMenu() {
        System.out.println("1. print all students");
        System.out.println("2. find by id");
        System.out.println("3. paixu");
        System.out.println("4. exit");
    }
    public void startup() throws IOException {
        this.printMenu();
        Scanner scanner = new Scanner(System.in);
        int command = scanner.nextInt();
        while(command != 4) {
            if (command == 1) {
                StudentManager.printAll();
            } else if (command == 2) {
                StudentManager.getStudentById("222021321072019");
            }else if(command == 3){
                 StudentManager.paixu();
                }
            else
            command = scanner.nextInt();
        }
    }



}